1. Field of the Invention
The present invention relates to a power transmission device.
2. Description of the Related Art
Heretofore, as this kind of power transmission device, one which includes a differential ring gear which rotates and thereby scoops up lubricating oil accumulated in a bottom portion in a transmission case, a catch tank which, as well as temporarily accumulating the lubricating oil, causes it to flow downward and supplies it to a counter drive gear and the like, a fluid introduction passage which introduces the lubricating oil scooped up by a differential ring gear disposed on an upper side in the case and supplies it to a lubrication and cooling pathway and the catch tank in the case, and an oil pump which is driven by a drive motor to supply the lubricating oil to each sliding and rolling portion in the case, has been proposed (for example, refer to JP-A-2009-250422). With this device, a lubrication of each lubrication target is carried out using the lubricating oil scooped up by the differential ring gear and the lubricating oil supplied by the oil pump.
Also, a power transmission device which includes an oil pump which, being mounted between a pump housing and a pump cover which demarcates a first housing chamber housing a torque converter and a second housing chamber housing a planetary gear train of a transmission, supplies lubricating oil to the torque converter and the like as hydraulic oil, wherein a lubricating oil passage is formed in the pump housing, a lubricating oil supply port passing through the cover is formed in a position in the pump cover aligned with the lubricating oil passage, and a communication groove, which allows communication between the lubricating oil supply port and the clutch plate side of brakes which selectively fix rotational elements of the planetary gear train, is formed on a perimeter of the lubricating oil supply port, has also been proposed (for example, refer to JP-A-2007-85409). With the device, most of the oil is introduced into an oil passage connecting with the torque converter side, but one portion of the oil is drained to the lubricating oil passage and flows to the clutch plate side via the lubricating oil passage, lubricating oil supply port, and communication groove, thereby carrying out a lubrication of this clutch plate and the like.